Consider the points R (3, 0), A (0, -2), M (-5, -2) and P (-5, 2). If they are joined in the same order, predict: (A) Two sides of RAMP that are perpendicular to each other. (B) One side of RAMP that is parallel to one of the axes. (C) Two points that are mirror images of each other in one axis. Which axis will this be? Now plot the points and verify your predictions.

Chapter 1

Orienting Yourself: The Use of Coordinates

CBSE Class 9

Mathematics Solutions

Question:

Consider the points R (3, 0), A (0, -2), M (-5, -2) and P (-5, 2). If they are joined in the same order, predict:

(A) Two sides of $\mathrm{RAMP}$ that are perpendicular to each other.

(B) One side of $\mathrm{RAMP}$ that is parallel to one of the axes.

(C) Two points that are mirror images of each other in one axis. Which axis will this be? Now plot the points and verify your predictions.

Answer: Verified

On plotting the points in the cartesian plane:

(A) A horizontal line and a vertical line are perpendicular.
So, $AM \perp MP$ .

(B) $AM$ has slope 0, so $AM$ is parallel to the $x$ -axis.
Also, $MP$ is parallel to the $y$ -axis.

(C) $M(-5, -2)$ and $P(-5, 2)$ has same $x$ -coordinate and opposite $y$ -coordinates. They are mirror images in the $x$ -axis.

(All Q's of this Chapter solved)